Herman Cain predicted today that he’ll finish in the top three in the Iowa Republican Straw Poll in August — without shady tactics or breaking the bank.

Cain, in an interview on the Iowa Tea Party’s bus in Marshalltown, said he’s heard rumors and some candidates have paid people to attend the straw poll in the past.

“We are going to have very nice display but we’re not going to go overboard in terms of bells and whistles, Cain said. “Secondly, we’re not going to try and buy votes like it is rumored that some people have done in the past. I’m just saying.”

I asked who he thought might have tried to buy votes. “No, no. I’m just saying, we just hear that some people have done that in the past,” he said.

Cain said his campaign will furnish straw poll tickets, which cost $30, for supporters to attend. But, he said, “We’re not going to buy the ticket and then pay them $50 to come so they can have a good time so they can go vote in the straw poll.”

The straw poll has been criticized because candidates routinely bus supporters to the Ames event and buy their tickets to attend. Some have said that’s tantamount to buying votes. But Cain is taking the allegation up another notch, suggesting candidates may have paid people to attend.

It’s not the first time such rumors have circulated, but it’s the first time I’ve heard it directly from a candidate. It’s hard to fathom why Cain would raise credibility questions about the event while vowing to finish in the top three. It’s bound to raise hackles among Iowa GOP officials.

Update: Indeed. Casey Mills, Republican Party of Iowa spokesman, had this to say: “I have never once heard of that happening. Unsubstantiated rumors aside, the truth is that the Ames Straw poll tests both a campaign’s organizational strength and how well a candidate’s message resonates with caucusgoers.”